CHARACTERIZATION OF A M6 HYPOMORPHIC MUTANT IN THE FRUIT FLY

ZAPPIA MP; BILLI, SILVIA; REZABAL, CAROLINA; MARCELA ADRIANA BROCCO; CERIANI, MF; FRASCH, A. C.

Huerta Grande-Córdoba

Congreso; I Reunión Conjunta de Neurociencias (IRCN); 2009

Neuronal remodeling is a fundamental process by which the brain responds to environmental influences during stress. The glycoprotein M6a, member of the ?Proteolipid proteins? (PLP), has recently been identified as a stress-responsive gene in the hippocampus of stressed animals. Our findings indicate that M6a plays an important role in neurite outgrowth and filopodium/spines formation. Evolutionary studies showed that m6 is the only member of the PLP family in Arthropods and bioinformatics analysis of the protein sequences revealed that M6a and M6 have structural homology. Based on this information we decided to characterize M6, the ortholog of M6a, in D. melanogaster. M6 hypomorphic mutant flies with reduced M6 expression level (40) were subjected to behavioral tests (climbing, locomotor activity, life span, rest/activity cycles) and exposed to stressful conditions (extreme temperatures, an oxidative agent and starvation). Interestingly, M6 mutant flies specifically exhibited reduced global locomotor activity. Next, we examined M6 expression in the fly brain employing a GFP enhancer trap line expressing GFP fused at the N-terminal of M6C isoform. M6 is expressed in the mushroom bodies, optic lobes and central body complex, but a more detailed analysis including specific structural markers is still required. During the characterization of the M6 hypomorph mutant we noticed that females are sterile. Eggs laid from M6 mutant flies showed severe defects, collapsing soon after they are laid. Immunohistochemistry is underway to shed light on this issue. In depth characterization of such phenotypes will enable us to study M6 function at the cellular and molecular level in both reproductive and nervous systems.